Smoking marijuana can lead to a greater risk of bronchitis, cough, and phlegm production.

Marijuana users are significantly more likely than nonusers to develop chronic mental disorders, including schizophrenia. Schizophrenia is a type of mental illness where people might see or hear things that aren't really there (hallucinations).

Eating foods or drinking beverages that contain marijuana have some different risks than smoking marijuana, including a greater risk of poisoning.

About 1 in 10 marijuana users will become addicted. For people who begin using before the age of 18, that number rises to 1 in 6.